U.S. patent number 9,398,456 [Application Number 14/201,620] was granted by the patent office on 2016-07-19 for electronic device with accessory-based transmit power control.
This patent grant is currently assigned to Apple Inc.. The grantee listed for this patent is Apple Inc.. Invention is credited to Digvijay A. Jadhav, Jonathan C. King, Indranil S. Sen.
United States Patent |
9,398,456 |
Jadhav , et al. |
July 19, 2016 |
Electronic device with accessory-based transmit power control
Abstract
An electronic device may be provided with wireless circuitry for
transmitting and receiving wireless signals. Control circuitry may
be used to adjust transmit power levels for the wireless signals
and other settings for the wireless circuitry. The electronic
device may be operated in conjunction with an external accessory.
The accessory may be equipment that includes a dock connector, a
case to enclose the electronic device, equipment that is coupled to
the electronic device using a cable, or other external electronic
equipment. An identifier may be stored in the accessory. The impact
of the accessory on the wireless performance of the electronic
device may be characterized and associated with the identifier.
During operation of the electronic device, the electronic device
may adjust transmit power levels and other settings based on the
identifier of the accessory and based on sensor data, user input,
and other information.
Inventors: |
Jadhav; Digvijay A. (Sunnyvale,
CA), Sen; Indranil S. (Santa Clara, CA), King; Jonathan
C. (Santa Clara, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Assignee: |
Apple Inc. (Cupertino,
CA)
|
Family
ID: |
54018831 |
Appl.
No.: |
14/201,620 |
Filed: |
March 7, 2014 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20150257158 A1 |
Sep 10, 2015 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04M
1/72409 (20210101); H04W 52/04 (20130101); H04W
52/146 (20130101); H04W 12/06 (20130101); H04B
1/40 (20130101); H04B 1/3877 (20130101); H04W
52/281 (20130101); H04W 4/90 (20180201); H04W
52/283 (20130101); H04B 1/04 (20130101); H04M
2250/12 (20130101); H04W 52/247 (20130101); H04B
2001/0416 (20130101); H04W 52/248 (20130101); H04M
1/72418 (20210101) |
Current International
Class: |
H04M
1/00 (20060101); H04B 1/40 (20150101); H04B
1/04 (20060101); H04W 12/06 (20090101); H04B
1/3877 (20150101); H04M 1/725 (20060101); H04W
52/28 (20090101); H04W 52/14 (20090101); H04W
52/04 (20090101); H04W 4/22 (20090101); H04W
52/24 (20090101) |
Field of
Search: |
;455/550.1,522,556.1,404.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1343380 |
|
Apr 2002 |
|
CN |
|
1696743 |
|
Nov 2005 |
|
CN |
|
1747228 |
|
Jun 2006 |
|
CN |
|
101053170 |
|
Oct 2007 |
|
CN |
|
101330162 |
|
Dec 2008 |
|
CN |
|
102005035935 |
|
Feb 2007 |
|
DE |
|
0 564 164 |
|
Oct 1993 |
|
EP |
|
1298809 |
|
Apr 2003 |
|
EP |
|
1 469 550 |
|
Oct 2004 |
|
EP |
|
1 524 774 |
|
Apr 2005 |
|
EP |
|
1564896 |
|
Aug 2005 |
|
EP |
|
2 380 359 |
|
Apr 2003 |
|
GB |
|
2003179670 |
|
Jun 2003 |
|
JP |
|
2003209483 |
|
Jul 2003 |
|
JP |
|
2003216318 |
|
Jul 2003 |
|
JP |
|
200667061 |
|
Mar 2006 |
|
JP |
|
2006218083 |
|
Aug 2006 |
|
JP |
|
2008009759 |
|
Jan 2008 |
|
JP |
|
2008011292 |
|
Jan 2008 |
|
JP |
|
2008537615 |
|
Sep 2008 |
|
JP |
|
2009032570 |
|
Feb 2009 |
|
JP |
|
0131733 |
|
May 2001 |
|
WO |
|
02/05443 |
|
Jan 2002 |
|
WO |
|
2005112280 |
|
Nov 2005 |
|
WO |
|
2007116790 |
|
Oct 2007 |
|
WO |
|
2008/078142 |
|
Jul 2008 |
|
WO |
|
2009022387 |
|
Feb 2009 |
|
WO |
|
2009149023 |
|
Dec 2009 |
|
WO |
|
2013165419 |
|
Nov 2013 |
|
WO |
|
Other References
Schlub et al., U.S. Appl. No. 13/865,578, filed Apr. 18, 2013.
cited by applicant .
Myllmaki et al., "Capacitive recognition of the user's hand grip
position in mobile handsets", Progress in Electromagnetics Research
B, vol. 22, 2010, pp. 203-220. cited by applicant .
Breeden, "Audible Message Alert With Ear Proximity Detector for
Portable Handsets," Motorola, Inc. Technical Developments, vol. 12,
Apr. (p. 102-103). cited by applicant .
"CapTouch Programmable Controller for Single-Electrode Capacitance
Sensors", AD7147 Data Sheet Rev. B, [online], Analog Devices, Inc.,
[retrieved on Dec. 7, 2009], <URL:
http://www.analog.com/static/imported-files/data.sub.--sheets/AD7147.pdf&-
gt;. cited by applicant.
|
Primary Examiner: Le; Danh
Attorney, Agent or Firm: Treyz Law Group, P.C. Treyz; G.
Victor Lyons; Michael H.
Claims
What is claimed is:
1. An electronic device configured to couple to an external
accessory, comprising: an antenna; wireless radio-frequency
transceiver circuitry that transmits wireless signals at a wireless
transmit power level using the antenna; and control circuitry that
receives an identifier from the accessory and that controls the
wireless radio-frequency transceiver circuitry to adjust the
wireless transmit power level based on the identifier and based on
transmit power commands received from a wireless base station.
2. The electronic device defined in claim 1 further comprising a
proximity sensor, wherein the control circuitry is configured to
control the wireless radio-frequency transceiver circuitry to
adjust the wireless transmit power level based on data from the
proximity sensor.
3. The electronic device defined in claim 2, wherein the control
circuitry is configured to control the wireless radio-frequency
transceiver circuitry to adjust the wireless transmit power level
to one of first, second, and third different transmit power levels
based on the data from the proximity sensor and to one of fourth
and fifth different transmit power levels based on the identifier,
wherein the third and fourth transmit power levels are greater than
the first, second, and third transmit power levels.
4. The electronic device defined in claim 1 further comprising
input-output circuitry that receives user input from a user,
wherein the control circuitry is configured to control the wireless
radio-frequency transceiver circuitry to adjust the wireless
transmit power level based on the user input.
5. The electronic device defined in claim 4 wherein the user input
comprises an emergency authorization and wherein the input-output
circuitry comprises circuitry that receives the emergency
authorization.
6. The electronic device defined in claim 4 wherein the
input-output circuitry comprises a touch screen display and wherein
the user input comprises an authorization received through the
touch screen display.
7. The electronic device defined in claim 1 wherein the accessory
has a dock, the electronic device further comprising: a connector
that is coupled to the dock.
8. The electronic device defined in claim 1 wherein the accessory
is a case, the electronic device further comprising a magnetic
sensor that senses the identifier by detecting magnetic signals
from the case with the magnetic sensor.
9. The electronic device defined in claim 1 further comprising a
sensor, wherein the control circuitry is configured to adjust the
wireless transmit power based on data from the sensor.
10. The electronic device defined in claim 9 wherein the sensor
comprises an accelerometer.
11. The electronic device defined in claim 9 wherein the sensor
comprises a capacitive proximity sensor.
12. The electronic device defined in claim 9 wherein the sensor
comprises a light-based proximity sensor.
13. The electronic device defined in claim 9 wherein the sensor
comprises an audio sensor.
14. The electronic device defined in claim 1 further comprising a
housing with a connector port, wherein the accessory is coupled to
the connector port.
15. The electronic device defined in claim 1 further comprising: an
additional antenna; and switching circuitry that selectively
couples the antenna and the additional antenna to the wireless
radio-frequency transceiver circuitry, wherein the control
circuitry is configured to couple a selected one of the antenna and
the additional antenna to the wireless transceiver circuitry based
on the identifier.
16. The electronic device defined in claim 1 wherein the antenna
comprises a tunable antenna and wherein the control circuitry is
configured to tune the antenna based on the identifier.
17. The electronic device defined in claim 1, wherein the
transmitted wireless signals comprise wireless data that is
transmitted at the wireless power level to external communications
equipment that is separate from the external accessory.
18. The electronic device defined in claim 1, wherein the control
circuitry is configured to control the wireless radio-frequency
transceiver circuitry to reduce the wireless transmit power level
based on the received identifier.
19. A portable electronic device configured to be coupled to an
external accessory in which an accessory identifier for that
accessory is stored, comprising: a housing; a display mounted in
the housing; a proximity sensor mounted in the housing that
monitors for external objects adjacent to the housing; an antenna;
wireless radio-frequency transceiver circuitry that transmits
wireless signals at a wireless transmit power level using the
antenna; input-output circuitry; a connector; and control circuitry
that receives user input from a user with the input-output
circuitry and that receives the accessory identifier with the
connector, wherein the control circuitry controls the wireless
radio-frequency transceiver circuitry to adjust the wireless
transmit power level based on the user input, the accessory
identifier, and transmit power commands received from a wireless
base station.
20. The portable electronic device defined in claim 19 wherein the
accessory comprises in-vehicle equipment and wherein the user input
comprises an emergency responder authorization.
Description
BACKGROUND
This relates generally to electronic devices and, more
particularly, to electronic devices with wireless communications
circuitry.
Electronic devices often include wireless communications circuitry.
For example, cellular telephones, computers, and other devices
often contain antennas and wireless transceivers for supporting
wireless communications.
It can be challenging to achieve desired wireless communications
performance targets in electronic devices, particularly when a
device is portable and compact. As a device is moved to different
locations in a wireless network, it may be necessary to increase
and decrease the amount of power that is transmitted during
wireless communications to satisfy network requirements. Regulatory
bodies may also impose constraints on how much power can be
transmitted by a device. At the same time, users are seeking
optimum wireless performance. These constraints may conflict, but
such conflicts may be difficult to resolve satisfactorily.
It would therefore be desirable to be able to provide improved ways
for controlling wireless performance in an electronic device such
as the amount of power transmitted by the electronic device during
wireless communications.
SUMMARY
An electronic device may be provided with wireless circuitry. The
electronic device may be a portable electronic device such as a
cellular telephone or tablet computer, or may be other electronic
equipment.
The wireless circuitry in the electronic device may include
radio-frequency transceiver circuitry and one or more antennas for
transmitting and receiving wireless signals. The radio-frequency
transceiver circuitry may include a transceiver and a power
amplifier that can be controlled in real time to adjust wireless
signal transmit power levels. During operation, control circuitry
may be used to adjust transmit power levels for the wireless
signals and other settings for the wireless circuitry.
The electronic device may be operated in conjunction with an
external accessory. The external accessory may be equipment that
includes a dock connector, a case to enclose the electronic device,
equipment that is coupled to the electronic device using a cable,
or other external electronic equipment. An identifier may be stored
in the external accessory. An accessory can be identified by the
electronic device using the identifier that is stored in the
accessory.
The impact of the external accessory on the wireless performance of
the electronic device may be characterized and associated with the
identifier. Some external accessories may influence the amount of
emitted wireless power in the vicinity of the electronic device.
For example, a case or an accessory with a dock may reduce emitted
radiation hotspots. By taking into account the hotspot-reducing
influence of attached accessories, an electronic device may be able
to optimize transmitted power settings to enhance wireless
performance.
If desired, user input from an authorized user, sensor data,
commands from a wireless base station, and other data may be used
in addition to the identifier to determine how to adjust wireless
transmit power levels. Additional actions may also be taken in
response to detection of a particular type of accessory identifier
or other input. For example, antennas can be selected for use,
antennas may be tuned, or other wireless settings may be adjusted
by the electronic device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an illustrative electronic device
with wireless communications circuitry in accordance with an
embodiment.
FIG. 2 is a schematic diagram of an illustrative electronic device
with wireless communications circuitry in accordance with an
embodiment.
FIG. 3 is a diagram of illustrative circuitry for selecting between
multiple antennas in accordance with an embodiment.
FIG. 4 is a diagram of an illustrative operating environment for a
wireless electronic device that can communicate with a wireless
base station and that can be coupled to an accessory device in
accordance with an embodiment.
FIG. 5 is a diagram of illustrative display screens that may be
displayed for a user in accordance with an embodiment.
FIG. 6 is a table showing how wireless transmit powers may be set
to different levels as a function of device status in accordance
with an embodiment.
FIG. 7 is a graph showing how wireless transmit power may be
adjusted over time as device status changes during operation in
accordance with an embodiment.
FIG. 8 is a flow chart of illustrative operations involved in
controlling wireless transmit power during use of an electronic
device in accordance with an embodiment.
DETAILED DESCRIPTION
An electronic device such as electronic device 10 of FIG. 1 may
contain wireless circuitry. For example, electronic device 10 may
contain wireless communications circuitry that operates in
long-range communications bands such as cellular telephone bands
and wireless circuitry that operates in short-range communications
bands such as the 2.4 GHz Bluetooth.RTM. band and the 2.4 GHz and 5
GHz WiFi.RTM. wireless local area network bands (sometimes referred
to as IEEE 802.11 bands or wireless local area network
communications bands). Device 10 may also contain wireless
communications circuitry for implementing near-field
communications, communications at 60 GHz, light-based wireless
communications, satellite navigation system communications, or
other wireless communications.
An electronic device such as electronic device 10 of FIG. 1 may be
a computing device such as a laptop computer, a computer monitor
containing an embedded computer, a tablet computer, a cellular
telephone, a media player, or other handheld or portable electronic
device, a smaller device such as a wrist-watch device, a pendant
device, a headphone or earpiece device, or other wearable or
miniature device, a television, a computer display that does not
contain an embedded computer, a gaming device, a navigation device,
an embedded system such as a system in which electronic equipment
with a display is mounted in a kiosk or automobile, equipment that
implements the functionality of two or more of these devices, or
other electronic equipment. In the illustrative configuration of
FIG. 1, device 10 is a portable device such as a cellular
telephone, media player, tablet computer, or other portable
computing device. Other configurations may be used for device 10 if
desired. The example of FIG. 1 is merely illustrative.
In the example of FIG. 1, device 10 includes a display such as
display 14. Display 14 has been mounted in a housing such as
housing 12. Housing 12, which may sometimes be referred to as an
enclosure or case, may be formed of plastic, glass, ceramics, fiber
composites, metal (e.g., stainless steel, aluminum, etc.), other
suitable materials, or a combination of any two or more of these
materials. Housing 12 may be formed using a unibody configuration
in which some or all of housing 12 is machined or molded as a
single structure or may be formed using multiple structures (e.g.,
an internal frame structure, one or more structures that form
exterior housing surfaces, etc.).
Display 14 may be a touch screen display that incorporates a layer
of conductive capacitive touch sensor electrodes or other touch
sensor components (e.g., resistive touch sensor components,
acoustic touch sensor components, force-based touch sensor
components, light-based touch sensor components, etc.) or may be a
display that is not touch-sensitive. Capacitive touch screen
electrodes may be formed from an array of indium tin oxide pads or
other transparent conductive structures.
Display 14 may include an array of display pixels formed from
liquid crystal display (LCD) components, an array of
electrophoretic display pixels, an array of plasma display pixels,
an array of organic light-emitting diode display pixels, an array
of electrowetting display pixels, or display pixels based on other
display technologies.
Display 14 may be protected using a display cover layer such as a
layer of transparent glass or clear plastic. Openings may be formed
in the display cover layer. For example, an opening may be formed
in the display cover layer to accommodate a button such as button
16. An opening may also be formed in the display cover layer to
accommodate ports such as speaker port 18. Openings such as opening
20 may be formed in housing 12 to form communications ports (e.g.,
an audio jack port, a digital data port, etc.).
A schematic diagram showing illustrative components that may be
used in device 10 is shown in FIG. 2. As shown in FIG. 2, device 10
may include control circuitry such as storage and processing
circuitry 30. Storage and processing circuitry 30 may include
storage such as hard disk drive storage, nonvolatile memory (e.g.,
flash memory or other electrically-programmable-read-only memory
configured to form a solid state drive), volatile memory (e.g.,
static or dynamic random-access-memory), etc. Processing circuitry
in storage and processing circuitry 30 may be used to control the
operation of device 10. This processing circuitry may be based on
one or more microprocessors, microcontrollers, digital signal
processors, application specific integrated circuits, etc.
Storage and processing circuitry 30 may be used to run software on
device 10, such as internet browsing applications,
voice-over-internet-protocol (VOIP) telephone call applications,
email applications, media playback applications, operating system
functions, etc. To support interactions with external equipment,
storage and processing circuitry 30 may be used in implementing
communications protocols. Communications protocols that may be
implemented using storage and processing circuitry 30 include
internet protocols, wireless local area network protocols (e.g.,
IEEE 802.11 protocols--sometimes referred to as WiFi.RTM.),
protocols for other short-range wireless communications links such
as the Bluetooth.RTM. protocol, cellular telephone protocols, MIMO
protocols, antenna diversity protocols, etc.
Device 10 may include input-output circuitry 44. Input-output
circuitry 44 may include input-output devices 32. Input-output
devices 32 may be used to allow data to be supplied to device 10
and to allow data to be provided from device 10 to external
devices. Input-output devices 32 may include user interface
devices, data port devices, and other input-output components. For
example, input-output devices may include touch screens, displays
without touch sensor capabilities, buttons, joysticks, click
wheels, scrolling wheels, touch pads, key pads, keyboards,
microphones, cameras, buttons, speakers, status indicators, light
sources, audio jacks and other audio port components, digital data
port devices, light sensors, motion sensors (accelerometers),
capacitance sensors, proximity sensors (e.g., a capacitive
proximity sensor and/or an infrared proximity sensor), magnetic
sensors, connector port sensors that determine whether a connector
such as an audio jack and/or digital data connector have been
inserted in a connector port in device 10, a connector port sensor
or other sensor that determines whether device 10 is mounted in a
dock, other sensors for determining whether device 10 is coupled to
an accessory, and other sensors and input-output components.
Input-output circuitry 44 may include wireless communications
circuitry 34 for communicating wirelessly with external equipment.
Wireless communications circuitry 34 may include radio-frequency
(RF) transceiver circuitry formed from one or more integrated
circuits, power amplifier circuitry, low-noise input amplifiers,
passive RF components, one or more antennas, transmission lines,
and other circuitry for handling RF wireless signals. Wireless
signals can also be sent using light (e.g., using infrared
communications).
Wireless communications circuitry 34 may include radio-frequency
transceiver circuitry 90 for handling various radio-frequency
communications bands. For example, circuitry 34 may include
transceiver circuitry 36, 38, and 42. Transceiver circuitry 36 may
be wireless local area network transceiver circuitry that may
handle 2.4 GHz and 5 GHz bands for WiFi.RTM. (IEEE 802.11)
communications and that may handle the 2.4 GHz Bluetooth.RTM.
communications band. Circuitry 34 may use cellular telephone
transceiver circuitry 38 for handling wireless communications in
frequency ranges such as a low communications band from 700 to 960
MHz, a midband from 1710 to 2170 MHz, and a high band from 2300 to
2700 MHz or other communications bands between 700 MHz and 2700 MHz
or other suitable frequencies (as examples). Circuitry 38 may
handle voice data and non-voice data. Wireless communications
circuitry 34 can include circuitry for other short-range and
long-range wireless links if desired. For example, wireless
communications circuitry 34 may include 60 GHz transceiver
circuitry, circuitry for receiving television and radio signals,
paging system transceivers, near field communications (NFC)
circuitry, etc. Wireless communications circuitry 34 may include
satellite navigation system circuitry such as global positioning
system (GPS) receiver circuitry 42 for receiving GPS signals at
1575 MHz or for handling other satellite positioning data. In
WiFi.RTM. and Bluetooth.RTM. links and other short-range wireless
links, wireless signals are typically used to convey data over tens
or hundreds of feet. In cellular telephone links and other
long-range links, wireless signals are typically used to convey
data over thousands of feet or miles.
Wireless communications circuitry 34 may include antennas 40.
Antennas 40 may be formed using any suitable antenna types. For
example, antennas 40 may include antennas with resonating elements
that are formed from loop antenna structures, patch antenna
structures, inverted-F antenna structures, slot antenna structures,
planar inverted-F antenna structures, helical antenna structures,
hybrids of these designs, etc. If desired, one or more of antennas
40 may be cavity-backed antennas. Different types of antennas may
be used for different bands and combinations of bands. For example,
one type of antenna may be used in forming a local wireless link
antenna and another type of antenna may be used in forming a remote
wireless link antenna.
Transmission line paths may be used to couple antenna structures 40
to transceiver circuitry 90. Transmission lines in device 10 may
include coaxial cable paths, microstrip transmission lines,
stripline transmission lines, edge-coupled microstrip transmission
lines, edge-coupled stripline transmission lines, transmission
lines formed from combinations of transmission lines of these
types, etc. Filter circuitry, switching circuitry, impedance
matching circuitry, and other circuitry may be interposed within
the transmission lines, if desired.
Device 10 may contain multiple antennas 40. One or more of the
antennas may be blocked by a user's body or other external object
while one or more other antennas are not blocked. If desired,
control circuitry 30 may be used to select an optimum antenna to
use in device 10 in real time. Control circuitry 30 may, for
example, make an antenna selection based on information on received
signal strength, based on sensor data (e.g., information from a
proximity sensor indicating which of multiple antennas may be
blocked by an external object), or based on other information.
With one suitable arrangement, device 10 obtains information on
which external accessories are coupled to device 10. For example,
device 10 may determine whether device 10 has been mounted in a
dock in an accessory, whether an accessory such as a headset or
other device with a cable has been plugged into a port on device
10, or whether device 10 is otherwise being used in conjunction
with an accessory. In situations such as these, it may be desirable
to take actions with device 10 that are based on the current
operating environment for device 10. As an example, device 10 may
select an antenna to use based on which accessory or type of
accessory is being used with device 10, device 10 may adjust
transmit power levels based on which accessory or type of accessory
is being used with device 10, or may take other actions based on
which accessory or type of accessory is being used with device
10.
FIG. 3 is a schematic diagram of a portion of an illustrative
device that includes multiple antennas. As shown in the example of
FIG. 3, switching circuitry such as multiplexer 100 may be used to
couple antennas 40A and 40B to radio-frequency transceiver
circuitry 90. Control lines such as control lines 102, 104, and 106
may receive control signals from control circuitry 30. In response
to information on which accessory or type of accessory is being
used with device 10 or other information (e.g., information from a
proximity sensor, transmit power commands from a network base
stations, etc.), control circuitry 30 can issue control commands on
paths such as paths 102, 104, and 106. For example, a control
command issued on path 102 may be used to switch either antenna 40A
or antenna 40B into use by transceiver 90 (i.e., to transmit and/or
receive wireless antenna signals). Control paths may also be used
to control the wireless transceiver circuitry of device 10 such as
transceiver 90 and power amplifier 108. In particular, a control
command on path 106 may be used to adjust the output power for
transmitted antenna signals produced by transceiver 90 and/or a
control command on power amplifier control path 104 may be used to
adjust the output power for amplified transmitted antenna signals
at the output of power amplifier 108. In general, the wireless
transmit power level for device 10 may be adjusted by adjusting the
output power from transceiver 90 and/or from power amplifier
circuitry such as power amplifier 108.
FIG. 4 is a circuit diagram of device 10 and external equipment
that may be used with device 10 such as accessory 126 and wireless
base station 136. Device 10 may use radio-frequency transceiver
circuitry 90 and antenna(s) 40 to communicate with wireless base
station 136. During operation, device 10 may use transceiver
circuitry 90 and antenna(s) 40 to transmit wireless signals 134 to
base station 136 and may use transceiver circuitry 90 and
antenna(s) 40 to receive wireless signals 134. Base station 136 may
be a cellular telephone base station, a wireless local area network
base station, or other external wireless equipment that supports
wireless communications with device 10.
Device 10 may include sensors such as proximity sensor 110.
Proximity sensor 110 may be a light-based proximity sensor, a
capacitive proximity sensor, and/or a proximity sensor based on
other technologies. An illustrative light-based proximity sensor
may include a light emitter such as an infrared light-emitting
diode and may have a light sensor such as a photodetector. A
capacitive proximity sensor may have capacitor electrode structures
that measure changes in capacitance due to the presence of external
objects. Using proximity sensor 110, device 10 can monitor for the
presence of external objects such as object 112 in the vicinity of
device 10. For example, device 10 can use readings from proximity
sensor 110 to determine when an external object such as a user's
body or other object are within a given distance of device 10
and/or may obtain other proximity sensor data.
Electronic device 10 may operate in conjunction with one or more
external electronic devices such as accessory 126. Accessory 126
may include some or all of the components in electronic device 10
of FIG. 2. Examples of accessories that may be used with device 10
include a headset with an audio cable or digital cable that mates
with device 10, a speaker with an audio cable or digital cable that
mates with device 10, a clock radio with a dock that receives
device 10, a powered speaker that contains a dock that receives
device 10, a head unit, audio system, navigation system, or other
electrical equipment in a vehicle that has a dock or cable that
receives device 10, a keyboard that mates with device 10, a cover
(e.g., a leather or plastic case) that receives device 10 and that
may optionally have a keyboard or other component that mates with
device 10, or other external equipment.
Accessory 126 may have one or more connectors such as connector
120. Connector 120 may be an audio jack connector (e.g., a
tip-ring-sleeve connector, a tip-ring-ring-sleeve connector or
other audio jack connector having a 1/8'' diameter or a 1/4''
diameter or other suitable diameter), may be a digital data
connector (e.g., a data connector with one or more digital data
lines and one or more power lines such as a Universal Serial Bus
connector or other connector having a differential digital data
line pair and a pair of positive and ground power lines), may be a
connector that supports a combination of analog and data signals on
shared lines and/or on dedicated analog lines and dedicated digital
lines, or may be any other suitable type of connector. Connector
120 may be mounted within a connector port in a housing for
accessory 126, may be attached to the end of a cable that is
plugged into accessory 126 or that serves as a pigtail for
accessory 126, or may otherwise be coupled to accessory 126.
Device 10 may have a connector such as connector 114 that mates
with connector 120 of accessory 126. Connectors such as connectors
114 and 120 may have contacts (sometimes referred to as pins). For
example, connector 114 may have contacts 116 and connector 120 may
have contacts 118. There may be any suitable number of contacts in
the connectors of device 10 and accessory 126. For example,
connector 114 may have four contacts 116 and connector 120 may have
four mating contacts 120. Configurations for connectors 114 and 120
that have fewer than four contacts or more than four contacts may
also be used. The configuration of FIG. 4 in which connector 114
has four contacts 116 and connector 120 has four contacts 118 is
merely illustrative.
During operation of device 10, wireless base station 136 may send
commands to device 10 that instruct device 10 to raise or lower the
transmit power level associated with wireless signals 134 that are
being transmitted by radio-frequency transceiver circuitry 90 and
antenna(s) 40. If transmit powers are too low, link quality between
device 10 and wireless base station 136 will be low. If, however,
transmit powers are too high, device 10 may cause wireless
interference that prevents other devices in the network from
communicating effectively with wireless base station 136. The
commands issued by wireless base station 136 to device 10 (and
other devices in the network) raise and lower transmit power to
balance these concerns. The commands to raise and lower transit
power levels are sometimes referred to as TPC commands or transmit
power commands.
Device 10 may use input-output circuitry 44 to gather user input
132 from a user of device 10. For example, a user may press one or
more buttons in device 10, may provide voice commands to device 10,
may enter information into a touch screen (e.g., by pressing
on-screen buttons or otherwise selecting on-screen options on
display 14), or may otherwise supply input to device 10. User input
132 may be used in controlling the software running on device 10,
which, in turn, controls the operation of device 10.
Device 10 may take actions that depend on the identity of accessory
126. For example, wireless circuit adjustments and other
adjustments may be made based on which type of accessory is coupled
to device 10. Accessory 126 may contain control circuitry and
input-output circuitry 124. An integrated circuit in circuitry 124
or other circuitry 124 (e.g., registers, a memory circuit, etc.)
may be used to store an accessory identifier (ID). The identifier
may uniquely identify accessory 126 and/or may identify accessory
126 as being part of a larger class (or classes) of device. As an
example, the identifier information stored in circuitry 124 may
specify that accessory 126 is a headset or a particular class of
headset, may specify that accessory 126 is a dock or is a dock in a
particular type of environment such as an in-vehicle dock, may
specify that accessory 126 is a case or is a particular type of
case (e.g., a case with a hinge, a case without a hinge, a case
with a particular thickness or a particular set of radio-frequency
characteristics, etc.), or may specify that accessory 126 has other
characteristics.
If desired, the identifier may be stored in accessory 126 using one
or more resistors such as resistor 122 (e.g., resistors that are
shorted between contacts 118 in connector 120). When device 10 and
accessory 126 are coupled by attaching connectors 114 and 120
together, control circuitry 30 in device 10 can evaluate the
resistance values of the one or more resistors 122 in accessory 126
to determine that identifier. Magnets such as magnet 128 may also
be used to store identifiers in accessories 126 (e.g., in
accessories such as a case that can receive device 10, etc.). The
properties of the magnet(s) may be monitored by device 10 using
magnetic sensors in device 10 such as magnetic sensor 130.
Information may be encoded based on magnet strength, magnetic
polarity, magnet location within the case or other accessory,
etc.
Regardless of how device 10 obtains identifier information from
accessory 126, the identifier that is obtained may be used to
specify characteristics about accessory 126 that are used in
adjusting the operation of device 10 (e.g., wireless operation,
etc.). As an example, the accessory identifier may be correlated
with radio-frequency properties such as the propensity of accessory
126 to attenuate wireless signal powers in the vicinity of antenna
40. This relationship between accessory identifier and the wireless
behavior of device 10 when device 10 is coupled to accessory 126
allows device 10 to control radio-frequency transmit powers for the
wireless antenna signals 134 that are being transmitted by
radio-frequency transceiver 90 and antenna(s) 40 based on the
identity of accessory 126.
To ensure that regulatory limits are met for wireless emissions in
the vicinity of a user's body, device 10 may impose a wireless
transmit power limit on transmitted wireless signals 134. The
transmit power limit may vary as a function of wireless frequency
(or communications band) or as a function of other wireless
communications parameters (e.g., communications protocol, etc.).
Abiding by the transmit power limit specified by regulatory bodies
ensures that device 10 will be operated safely.
In some situations, such as when device 10 is being held in a
user's hand, pressed against a user's head, or rested on a user's
lap, it may be desirable to reduce the transmit power for device 10
to ensure that regulatory limits for emitted radiation are
satisfied. Proximity sensor data from proximity sensor 110 can
determine when a user's body or other external object is present in
the vicinity of device 10, so that the transmit power can be
reduced accordingly.
When device 10 is being used with certain accessories, it may be
desirable to increase the transmit power to ensure that device 10
can communicate satisfactorily with wireless base stations 136 or
other external wireless equipment. Consider, as an example, a
scenario in which device 10 is mounted on a dock associated with
accessory 126 (i.e., a dock having a dock connector such as
connector 120). Because the dock is bulky and is associated with
equipment such as a clock radio, powered set of speakers, or
in-vehicle equipment, device 10 will be located far from the body
of the user. The presence of the accessory therefore allows
radio-frequency signals that are transmitted to decrease in
intensity before potentially reaching a user. In this type of
situation, it is safe to raise the wireless transmit power limit
for device 10 and it is desirable to do so to improve the quality
of wireless communications with external equipment such as wireless
base station 136. Signals from proximity sensor 110 may indicate
that an external object is close to device 10 when device 10 is
mounted in an accessory (e.g., a case or a device with a dock), but
because the external object is part of an inanimate object such as
the dock and is not part of a user's body, it is appropriate to
raise the transmit power limit. The power-reduction response of
device 10 that would otherwise be made in the presence of detecting
an external object in the vicinity of sensor 110 may be
suppressed.
Different types of accessories may have different radio-frequency
characteristics. For example, in some accessories, such as certain
accessories with docks, device 10 may be well isolated from contact
with a user's body. In other accessories, such as cases that
enclose device 10, device 10 may be well isolated from contact with
a user's body, but may not be as isolated as when device 10 is
mounted to an accessory dock. The identifier in accessory 126 (in
this example) can specify whether the accessory is equipment with a
dock (e.g., in-vehicle equipment) or is a case. When device 10
senses that accessory 126 is an accessory of the type that has a
dock, device 10 can set the maximum transmit power level to a first
level. In response to sensing that accessory 126 is a case, device
10 can establish a transmit power limit at a second level that is
lower than the first level. Each accessory can be characterized in
advance of use with device 10 and an appropriate identifier may be
stored in that accessory based on the ability of the accessory to
reduce hotspots in transmitted signal powers and otherwise
attenuate the power of wireless signals reaching a user.
In addition to controlling radio-frequency transmit powers for
signals 134 based on the identity of accessory 126, device 10 may
control radio-frequency transmit powers for signals 134 based on
user input 132, based on data from proximity sensor 110, based on
commands from wireless base station 136, and/or based on data from
other sensors and circuitry in device 10. Device 10 may also take
other actions based on these inputs. For example, device 10 may
take actions such as switching a desired antenna into use from a
set of multiple antennas, may tune one or more antennas in device
10, or may take other actions based on the identity of accessory
126, based on user input 132, based on data from proximity sensor
110, based on commands from wireless base station 136, and/or based
on data from other sensors and circuitry in device 10.
There is generally an interplay between the data received from
proximity sensor 110 and other sensors, an accessory identifier,
commands received from base stations 136 (e.g., transmit power
commands), and data from user input 132. Device 10 (e.g., control
circuitry 30) may implement a hierarchy that resolves conflicts
between data from different sources. As an example, if device 10
receives a TPC command from base station 136 that instructs device
10 to raise the transmit power level being used to transmit
wireless signals, that command will be followed unless a proximity
sensor signal from proximity sensor 110 indicates that there is an
external object in the vicinity of device 10. The presence of the
external object adjacent to device 10 indicates that device 10 may
be currently in use by a user who is resting device 10 on the
user's leg, is holding device 10, or is otherwise close to device
10. In this illustrative example, the data form the proximity
sensor is placed higher in the control hierarchy than the data from
the wireless base station. To ensure that device 10 does not
transmit signals that are too weak, even when it would be
appropriate to raise output powers, information from the identifier
in accessory 126 and/or user input 132 may be placed higher in the
control hierarchy than data from the proximity sensor.
As an example, if the identifier in accessory 126 indicates that
device 10 is currently mounted in a dock in an automobile while the
proximity sensor in device 10 is detecting a nearby object, device
10 can conclude that the proximity sensor in device 10 is sensing
the presence of the dock rather than a human body. As a result,
device 10 may allow the transmit power for wireless antenna signals
in device 10 to be raised above the reduced level that would
otherwise be set by the proximity sensor reading. The transmit
power may also, if desired, be raised above the normal transmit
power limit that would be imposed for device 10, because (in this
example), it is known that device 10 (i.e., the antenna in device
10 that is transmitting the wireless signals) is well separated
from the user's body.
As another example, a user may enter a special "emergency
responder" code into device 10 or other authorization that
certifies that the user is an authorized emergency responder
(personnel associated with a police force, fire department,
ambulance service, etc.) or is otherwise involved in an emergency
situation in which temporarily elevated wireless transmit powers
are appropriate. When device 10 receives the emergency responder
code, device 10 may temporarily raise the transmit power limit to
ensure that a satisfactory wireless communications link is
maintained between device 10 and wireless base station 136.
FIG. 5 shows illustrative display screens that may be displayed for
a user as the user provides device 10 with user input 132 such as
an emergency authorization code. Initially, display 14 of device 10
may display a screen for the user such as screen 140. Screen 140
may contain one or more on-screen options such as option 142.
Option 142 may be selected by the user when the user believes that
an emergency situation makes it appropriate to temporarily raise
the wireless transmit power limit for device 10. In response to
selection of on-screen option 142, device 10 may display screen 144
on display 14. Screen 144 may contain instructions such as
instructions 146 that direct the user to enter an authorization
code using on-screen options such as on-screen buttons 148. In
response to receiving an authorized code from the user via buttons
148, device 10 may display a screen such as screen 150 for the
user. Screen 150 may allow the user to make a cellular telephone
call by typing a desired telephone number into keypad keys such as
keys 152 and by pressing call option 154. Other on-screen options
may be used to allow the user to communicate using device 10 if
desired (e.g., text messaging options, email options, video call
options, voice communications options other than traditional
cellular telephone voice calls, etc.). When making the telephone
call or supporting other wireless communications, device 10 may
temporarily raise the wireless transmit power limit that is being
used by device 10.
FIG. 6 is a table showing how the maximum allowed transmit power
level in device 10 may be adjusted as a function of different
operating conditions in device 10. In the example of FIG. 6, if a
proximity sensor reading from proximity sensor 110 is high
(indicating that external object 112 is close to device 10), the
corresponding transmit power level may be set to a relatively low
value of P1. If, the proximity sensor reading is lower (i.e., a
medium value), the transmit power level may be raised to a slightly
higher value of P2 (i.e., a value above P1). When proximity sensor
readings are weak, external object 112 is relatively far from
device 10, so the transmit power may be set to a level of P3 that
is greater than P2. When device 10 is installed in an accessory of
type A (e.g., a case), antenna(s) 40 are shielded from direct
contact with a user by virtue of the presence of the case. As a
result, less radiated power can be absorbed into the user's body
and the maximum wireless transmit power for device 10 may be raised
to a level P4 that is greater than P3.
In response to detection that device 10 has been installed in an
accessory of type B (e.g., in a dock in an in-vehicle device), the
maximum wireless transmit power can be raised to an even higher
level of P5, due to the large separation between antenna 40 in
device 10 and the user. In emergency mode (e.g., when an emergency
responder or other user enters a value emergency authorization
code) or other user input 132, device 10 can set the transmit power
to a level of P5 that is greater than level P4 or an even higher
level (as examples).
During operation, transmit power commands from base station 136 can
be received and processed and may be used to further adjust the
current output power for device 10. For example, if the current
transmit power for device 10 is P3, TPC commands may temporarily
lower the transmit power to P2 if deemed necessary to prevent
interference in the network. As another example, if the maximum
transmit power has been set to level P5 to handle an emergency
situation, power-lowering TPC commands may be temporarily ignored.
Other types of transmit power control scenarios may be implemented
in device 10, if desired. The arrangement of FIG. 6 is merely
illustrative and is presented as an example of how different types
of sensor data, user input, and wireless base station command data
can be used in controlling wireless transmit power levels in device
10.
FIG. 7 is a graph showing an illustrative scenario in which
wireless transmit power P for device 10 is changed as a function of
time due to changes in received TPC commands, proximity sensor
data, other data on the operating conditions of device 10, a
detected accessory identifier, and/or user input. At times between
t0 and t1, device 10 is close to base station 136, so device 10 is
able to sustain a high quality wireless communications link between
device 10 and base station 136 while using relatively low transmit
powers. Base station 136 senses that device 10 is able to back off
transmit power to level P1 without unduly compromising link quality
and therefore issues TPC commands that reduce transmit power to
level P1. Between times t1 and t2, device 10 moves farther from
base station 136, so base station 136 directs device 10 to increase
its transmit power to level P2. Between times t2 and t3, device 10
has been moved to a location that is remote from base station 136,
so base station 136 issues a TPC command that directs device 10 to
increase wireless transmit power P to a relatively high level of
P3. Level P3 in this example, is the largest normally permitted
transmit power for device 10 that complies with regulatory limits
on emitted radiation (assuming device 10 is not installed within a
case, dock, or other equipment that increases the separation
between the user and the antennas in device 10).
Even though, at time t3, the maximum transmit power of P3 has been
requested by base station 136, data from proximity sensor 110 may
be used to override the transmit power level set by base station
136. This is illustrated by the reduced transmit power level of P2
that is used between times t3 and t4. In this example, base station
136 directed device 10 to use transmit power P3, but proximity
sensor 110 detected an external object at time t3 that was located
at a sufficiently close distance to dictate that the wireless
transmit power for device 10 should be reduced to transmit power
level P2. At times between t4 and t5, the external object is once
again located farther from device 10 and the transmit power is
accordingly allowed to rise to P3 again. If desired, operating mode
information (i.e., information that device 10 is using an ear
speaker and is therefore being held against the side of a user's
head) may be used to adjust wireless transmit power (see, e.g.,
illustrative transmit power level P1 between times t5 and t6).
Reduced power level P1 between times t5 and t6 may also result from
detection of the user's body using a light-based proximity sensor
or other sensor (e.g., an accelerometer that detects motion, a
sound sensor that detects absorption of ultrasonic tones emitted by
a speaker in device 10 by clothing on a user, temperature sensor
that indicates that the user is holding device 10, etc.).
In the FIG. 7 example, device 10 returns to normal maximum transmit
power P3 at times between t6 and t7 (i.e., TPC commands from base
station 136 have requested that device 10 transmit signals with its
normal maximum allowed power and no nearby object is present). In
this mode of operation, device 10 is fairly remote from base
station 136 and must therefore increase transmit power as much as
possible to sustain satisfactory communications. At times between
time t7 and t8, device 10 has been coupled to accessory 126. Device
10 detects the identifier stored in accessory 126 by reading the
identifier information through the connector in device 10 that is
coupled to accessory 126 and/or using magnetic sensing or other
identifier detection techniques. Accessory 126 partly shields the
user from radiated emissions, so it is appropriate for device to
further increase the transmit power level P to power P4 in response
to detection of the identifier. The type of identifier that is
received can be used by device 10 to determine how much transmit
power P can be increased. The ability to transmit signals at a
power P4 that is larger than the normal maximum of P3 helps enhance
wireless communications link quality while still satisfying
regulatory limits on emitted radiation levels in the vicinity of
device 10.
At times greater than t8 in the FIG. 7 example, an emergency
situation has made it necessary for the user to override the normal
internal transmit power controls in device 10. The user may, as an
example, supply device 10 with an emergency responder's code or
other authorization. When device 10 is instructed by the user input
that an emergency situation is present, device 10 temporarily
increases transmit power P to an elevated level of P5 (in this
example). The use of this elevated transmit power ensures that the
user can communicate with base station 136, even if the base
station is sufficiently remote from device 10 that communications
at lower powers such as transmit power P3 would be
unsuccessful.
A flow chart of illustrative steps involved in operating device 10
in a scenario in which multiple different types of data are used in
determining how to control the wireless transmit power and other
wireless behavior of device 10 are shown in FIG. 8. At step 200,
device 10 may perform monitoring operations to determine whether or
not operating conditions dictate a change in wireless transmit
power. Device 10 also uses wireless transceiver circuitry 90 and
antenna(s) 40 to transmits signals with the currently active
transmit power setting P during the operations of step 200. Base
station 136 receives and processes the transmitted signals and
transmits signals to device 10 that are received by device 10,
thereby maintaining a wireless link between device 10 and base
station 136.
During the monitoring operations of step 200, device 10 uses
control circuitry 30 to determine whether a transmit power command
has been received from base station 136 (see, e.g., line 204), to
determine whether proximity sensor data from proximity sensor 110
has been received that indicates that an external object is close
to device 10 (see, e.g., line 208), to determine whether an
accessory identifier has been received making it appropriate to
raise transmit power limits or take other actions (see, e.g., line
210), and to determine whether user input 132 or other data (e.g.,
data from other sensors or circuitry in device 10) has been
received (see, e.g., line 206). Using an established data
hierarchy, device 10 determines an appropriate transmit power level
P to use for device 10. The wireless transmit power P may then be
updated at step 202 before operations return to step 200, where
wireless signals are transmitted using the currently effective
transmit power.
If desired, additional actions and/or alternative actions may be
taken at step 202 based on the results of the monitoring operations
of step 200. In particular, device 10 may switch a desired antenna
into use based on the data collected during the monitoring
operations of step 200, may tune one or more antenna(s) 40 based on
the data collected during the monitoring operations of step 200, or
may take other appropriate actions. If, as an example, device 10
determines that an accessory such as a dock has been coupled to
device 10, device 10 may tune its antenna(s) to compensate for
antenna detuning resulting from the presence of the dock. As
another example, if device 10 determines that an emergency
situation is present, device 10 may switch one or more particular
antenna(s) into use to enhance transmit power capabilities for
device 10 or to otherwise optimize operation. Sensor data such as
temperature data, accelerometer data, audio data, and other data
may also be used in making these adjustments to the operation of
device 10, if desired.
The foregoing is merely illustrative and various modifications can
be made by those skilled in the art without departing from the
scope and spirit of the described embodiments. The foregoing
embodiments may be implemented individually or in any
combination.
* * * * *
References